Boerne Bean (Wildlife and Wildflowers of Texas - Wildflowers Pt. 1)

Boerne Bean

Phaseolus texensis

Blooming Season ³

September-November

Identification ³

(1) Herbaceous perennial VINES, trailing or climbing up to 7 m long, from tuberous taproots. STEMS terete, striate, lignescent at maturity, sparsely beset with hooked and retrose hairs. LEAVES with axillary buds sometimes developed at the base of the inflorescence; stipules lanceolate, 1.5–3.0 mm long, 0.8–1.2 mm wide, acute at tip, 3-veined, ascending to reflexed; petioles and rachises canaliculate, sparsely covered with hooked hairs; petioles 1.0–5.0 cm long; rachises 0.7–1.7 cm long; stipels subulateobovate, 1.0–2.5 mm long, ascending on terminal pulvinus and spreading on lateral pulvini; leaflets membranous to slightly chartaceous, terminal leaflets ovate to broadly so, occasionally round to quadrate lobed at base, 2.0–8.5 cm long, 2.0–7.0 cm wide; lateral leaflets ovate, sometimes basally lobed, acute at tip, apiculate, 1.5–7.0 cm long, 2.2–4.8 cm wide, rounded to subtruncate at base; upper and lower surfaces of leaflets sparsely covered with hooked hairs intermixed with antrorse-curved hairs. INFLORESCENCES of pseudoracemes, often minute secondary axes or stalks developed on floral nodes, main axis usually covered with hooked hairs; peduncles 5.0–10.0 cm long; rachises up to 12.0 cm long, with 5–13 floral nodes, each 2–3 flowered, often the middle one on a short stalk; primary nodal bracts triangular, 1.0–2.0 mm long, ca. 0.8 mm wide, 3-veined, persistent; secondary nodal bracts oblong, ca. 1 mm long, usually caducous; pedicels 4–9 mm long, sparsely covered with hooked hairs, arcuate in fruit; bracteoles ovate, ca. 0.5 mm long, 1-veined, persistent. CALYCES campanulate, 2.5–3.5 mm long, ca. 2.5 mm broad; inner surface covered with appressed hairs in the tube, outer surface with minute hooked and straight hairs on the lobe margins; upper lobe emarginate, laterals and lower lobes triangular, ca. 1.0 mm long. COROLLAS pink fading to dark pink, 1.2–1.5 cm long, ca. 7.0 mm high; standards oblong to orbicular, ca. 1.2 cm long, ca.1.0 cm wide, emarginate at apex, glabrous, lamina thickened at point of flexure, toward the base on both sides of claw bearing two flap-like appendages, tongue-guide surface concave and papillose, basal claws ca. 1.0 mm long; wings obovate, 1.2–1.5 cm long, ca. 8.0 mm wide, constricted toward base, upper basal margin folded and thickened, round-auriculate, claws ca. 4.0 mm long; keels 6.5–9.0 mm long, ca. 6.0 mm high, 1K closely-coiled diameter ca. 2.0 mm across, twisted and facing forward, transverse pouch ca. 1 mm long, claws of keel ca. 4.0 mm long. ANDROECIUM with vexillary stamen ca. 1.0 cm long with a globose appendage toward the base; staminal tube ca. 1.5 cm long, biauriculate toward the base, with 4 dorsifixed and 5 basifixed anthers, these oblong, ca. 0.6 mm long. POLLEN tricolporate, often with pseudocolpi, subtectate, finely reticulate. GYNOECIUM with nectary disc ca. 1.0 mm long; ovary linear, ca. 6.0 mm long, sericeous; ovules 5–7; style bearded introrsely; stigmas usually introrse; stigmattruncate or slightly lobed at base; next leaves
Phaseolus texensis can be distinguished from P. polystachios (section Paniculati), with which it has been considered recently conspecific (Freytag and Debouck, 2002), by a basic difference in inflorescence structure. The inflorescences of P. texensis are pseudoracemes, while those of P. polystachios are contracted panicles with lateral branches developing along the axis of the inflorescence.

Habitat ³

(1) Phaseolus texensis is restricted to the eastern and southern parts of the Edwards Plateau of Texas at elevations from 200 to 600 m. This species is usually found in small populations, in mixed woodlands, on limestone cliffs and outcrops, frequently along creeks. In Travis Co. this wild bean grows associated with Juniperus ashei J. Buchholz, Quercus buckleyi Nixon & Dorr, Ulmus crassifolia Nutt., Verbesina virginica L., Chasmanthium latifolium (Michx.) H.O. Yates, Desmodium paniculatum (L.) DC., Ruellia drummondiana (Nees) A. Gray, Ligustrum japonicum Thunb., Parthenocissus quinquefolia (L.) Planch., Rhamnus caroliniana Walter, Garrya lindheimeri Torr., Vitis sp., and Forestiera pubescens Nutt. In Kerr Co. it grows with Aster texanus E. S. Burgess, Brickellia cylindracea A. Gray & Engelm., Celtis reticulata Torr., Hamamelis virginiana L., Lindera benzoin (L.) Blume, Parthenocissus quinquefolia (L.) Planch., Platanus occidentalis L., Prunus serotina Ehrh., Quercus buckleyi, Q. laceyi Small, Q. muehlenbergii Engelm., Rhamnus caroliniana, Tilia americana L., Verbesina virginica L., and Vitis cinerea (Engelm.) Engelm. ex Millardet. The species epithet alludes to the distribution of this species, which is endemic to the state of Texas.